Newbie here, is there any tutorial or info that can show me how to do this. I want the UV to not be a circle but a rectangle, and I want to apply a tile shader/material that will evenly wrap around it. Then I want to bake the texture with the tiles on it. I want it to look like the image below.
You could start by marking some edges as seams. You can think of seams as cuts which make the mesh unwrapable. (It would work without seams, but this gives you more control.) It should look something like this:
Once you are done with that, select all faces and select “Follow active Quads” from the UV Mapping menu. This should result in a uv map like this:
Is that what you have been looking for?
As above; I create the seams, then I do UV/Reset on one face before selecting everything and UV/Follow Active Quads. I also use UV menu/scale to image bounds and fill the UV space since I often use things that repeat over the seams (or at least one of them).
The seam serves two purposes; quads stay connected as a rectangle rather than some pieces going upper left and other lower right, and also as an inspectional tool so I know where to zoom in looking for shading errors (tangents are not smoothed over the seam in aniso shading - it’s such a demoralizing limitation).